1. Field of the Invention
The present invention relates to an automatic on/off device for a lamp, and more particularly to a device for turning on a lamp when it detects a person entering a predetermined spatial area.
2. Description of the Related Art
A typical infrared sensor is mounted on top of a doorframe and is electrically connected to a lamp on the doorframe by a wire. When a person approaches the door, the lamp is turned on. Nevertheless, a long wire is required to connect the infrared sensor with the lamp. In addition, an extra wire is further required for connection with an indoor lighting device. Troublesome and costly installation is required when the indoor lighting device includes several lighting elements. The wires for connection are long and may be disconnected if the wires are inadvertently impinged. The internal metal cores in the wires may be exposed and cause injury if the outer insulating covering of the wires strips. An attempt to bury the wires in walls would require drilling and thus adversely affect the appearance of the walls, and the cost for drilling is high. Furthermore, installation of the infrared sensor requires a professional worker.
It is an object of the present invention to provide an automatic on/off device for a lamp that can be easily attached to the lamp by the user without the need of a professional worker.
It is another object of the present invention to provide an automatic on/off device that can be directly attached to a lamp that is currently in use without the need of long wires.
It is a further object of the present invention to provide an automatic on/off device that can be mounted in a lamp base for a lamp in a factory.
In accordance with a first aspect of the invention, an automatic on/off device comprises a sensing means including a power input end for contacting with a power connection of a lamp to form a circuit for controlling on/off of the lamp.
In accordance with a second aspect of the invention, an automatic on/off device comprises a mounting member removably attached to a lamp and a sensing means mounted in the mounting member. The sensing means includes a power input end for contacting with a power connection of the lamp to form a circuit for controlling on/off of the lamp.
In accordance with a third aspect of the invention, an automatic on/off device comprises a mounting member removably attached to a lamp, a sensing means mounted in the mounting member, and a panel. The mounting member has an opening in a side thereof. The sensing means includes an integrated circuit board, a control chip mounted on the integrated circuit board, and a sensor mounted in the mounting member and having a portion exposed outside the mounting member. The sensor includes a power input end for contacting with a power connection of the lamp to form a circuit for controlling on/off of the lamp under cooperation by the control chip. The panel is removably mounted to the side of the mounting member for covering the opening. The integrated circuit board is securely mounted to the panel.
In an embodiment of the invention, the mounting member includes an engaging slot, and the panel includes a protrusion for releasably engaging with the engaging slot. The lamp includes a fluorescent bulb having two ends. Each end of the fluorescent bulb has a base and two tube pins. The sensor has two leads in contact with the tube pins, respectively. The panel includes a slot through which the leads of the sensor extend out of the mounting member for contacting with the tube pins of the fluorescent bulb. The mounting member has a hole through which a portion of the sensor is exposed outside the lamp base. The sensor has a lower portion and a flange above the lower portion, wherein the flange has an outer diameter greater than a diameter of the hole of the mounting member and the lower portion of the sensor has an outer diameter smaller than the diameter of the hole of the mounting member.
Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.